Mercury-vapor rectifier



Patented Aug. 28, 1928.

UNITED STATES PATENT OFFICE.

OSKAR SEITZ, OF BADEN, SWITZERLAND, ASSIGNOR TO BROWN, BOVERI & QICEL, OF

BADEN, SWITZERLAND.

MERCURY-VAPOR RECTIFIER Application filed September 10, 1925, Serial No. 55,458, and in Germany October 29, 1924.

This invention relates to improvements in mercury vapor rectifiers and more particularly to improvements in and connected with the construction of the joints between the containing receptacles and the anodes of such rectifiers.

In mercury vapor rectifiers in which the containing vessels are of metal, ordinarily the holders by which the anodes are su ported, and which are insulated from t e vessel, are pressed by springs against the face of the insulating bushing or insulator,

said springs accommodating expansion of parts resulting from heating occurring in operation. Consequently, in spite of such expansion the joints around the passage by which the anodes are introduced are kept tight against the vacuum within the rectifier, so that mercury vapor can not pass through them.

Hitherto, the springs by which the effect of expansion due to heating has been compensated have been arranged outside the vessel, adjacent the passage by which they anodes are introduced. uch an arran ement has the disadvantage that the considerable friction of the mercury seal, which constitutes a kind of mercury stufling box, must be overcome on movement of the anode stem. Moreover, in order to prevent entrance of mercury vapor into the space within the insulating bushing, and in order to provide a uniform tightness and support, there is inserted as packing between the anode and the lower face of the insulator, a gasket of flexible and heat-resisting material, for example, asbestos.

In accordance with the present invention such a complication and the disadvantage of large stufiing box friction are avoided by introducing a movable packing or sealing means between the anode insulator and the anode stem within the rectifier vessel.

Certain structural arrangement embodying the invention are shown in the drawing for the purpose of illustration.

Fig. 1 is a sectional elevational view of one form of anode mounting,

Fig. 2 is a sectional elevational view of another form, and

Fig. 3 is' a sectional elevational view of a third form.

. Referring to the drawing, let it be understood that the reference numeral m designates a portion of the anode supporting plate which forms a cover for the cylinder or casing of the mercury vapor rectifier. An insulating bushing c extends through an opening in the plate m, the joint between the two being effectively closed by a suitable seal, as illustrated. The anode a has a, stem 6 positioned within the insulating bushing 0 and having screw thread engagement at its upper end with the anode holder is, the lower end ofwhich extends into the upper portion of the insulating bushing a and is sealed therein by a suitable seal .9. A nut n'is threaded onto the holder is above the upper end of the bushing 0 and engages the stop member t to clamp suitable packing discs to between said nut and the upper rim of the bushing. The head portion of the anode a presents a shoulder underlying the lower end of the bushing 0 throughout its circumference, and in this shoulder portion is formed an annular groove or channel a. Within this channel is disposed an annular sleeve member at which has a vertical flange makino a close fit with the wall ofthe groove an a horizontal flange which abuts the lower end of the bushin 0 throughout its circumference. A coile spring 6 is compressed within the groove, bearing at its lower end against the bottom of the channel and at its upper end against the horizontal flange of the sleeve member. By such arrangement the horizontal flange of the sleeve member is held in close sealing engagement with the lower end of the bushing 0, while the vertical flange forms a sliding seal against the outer wall of the channel. These seals are maintained incident to longitudinal expansion or contraction of the anode and are effective to prevent the entrance of mercury vapor into the space within the insulating bushing c. The pressure of the spring 6 is effective also to stress the nut n towards the upper end of the bushing c to exercise a proper clamping pressure upon the interposed sealing disc.

In the embodiment illustrated in Fig. 3 the sleeve member d has its lower end seated in an annular groove in the anode and forming a sliding seal against the outer wall of the groove, as at i. A shoulder on the lower end of the sleeve member d underlies the lower end of the bushing c and makes a sealing fit therewith. The sleeve member 03' extends into the bushing c to a position beyond a shoulder p on the anode stem, and at its end is provided withan inwardly turned annular flange A Spiral spring 6' is compressed between the flange j and the shoulder p so that its pressure holds the shoulder of sleeve member d in sealing engagement with the lower end of the bushing c at all times, while accommodatin longitudinal expansion and contraction of t e anode. By virtue of the sealing fit between the lower end of the sleeve member (1 and the anode head and end of the bushing 0, therefore, ingress of mercury vapor from the space It to the space within the bushing c is prevented.

In the embodiment illustrated in F i 2, a sliding seal between the bushing 0 and the anode stem is afi'orded by rings 3, in the nature of piston rings, which are seated in grooves in the anode stem and have a bearing fit against the interior surface of the bushing 0. This arrangement effectively seals off the chamber space it from the space g within the bushing '0, while accommodatin longitudinal extension and contraction o the anode and the associated parts.

It will be observed that one advantage of the invention resides in the fact that it avoids the necessity for any relative shiftin of parts which are connected by externa seals, such as the seal 8, while at the same time, it avoids the subjection of the insulating bushing to heavy pressures. A suitable close sealing fit between the shiftable sealing members, such as the sleeve members d, d and f, and the parts upon which they bear, may be obtained by grinding the coactin surfaces.

1. An electrode mounting for mercury vapor rectifiers comprising an insulating bushing .extending through the rectifier casing, an electrode having a portion within the bushing, and a sealing member having sealing engagement with the bushing and the electrode within the rectifier casing, said sealing member being shiftable with respect to one of said elements while maintaining sealing engagement therewith.

2. An electrode mountin for mercury vapor rectifiers comprising t e combination of an insulating bushing extending through the rectifier casing, an electrode having a portion within the bushing, and a sealing member within the rectifier casing and having sealing en a ement with one of said elements and shi table sealing engagement with the other thereof.

3. An electrode mounting for mercury vapor rectifiers comprising the combination of an insulating bushing extending within the rectifier casing, an electrode having a portion within the said bushing, and a metallic sealing member within the rectifier casing and having sealing engagement with the bushing and electrode, said sealing engagement with one of said elements being shiftable.

4. An electrode mountin for mercury vapor rectifiers comprising t e combination of an insulating bushing extending within the rectifier casing, an electrode having a portion within said bushing, and a sealing member having sealing engagement with the electrode and bushing to prevent entrance of mercury vapor within the bushing, said sealing member being shiftable with respect to one of said elements while in sealing engagement therewith.

5. An electrode mountin for mercury vapor rectifiers comprising t e combination of an insulating bushing extending into the rectifier casing, an electrode having a portion within the bushin and a sealing member co-operating with t e electrode and bushing to seal the latter against entrance of mercur vapor, said sealing member having shiftab e engagement with one of said elements to accommodate relative expansion and contraction of said elements.

6. An electrode mountin for mercury vapor rectifiers com rising t ecombination of an insulating bus ling element extending into the rectifier casing, an electrode element having a portion within said bushing, a sealing member within the rectifier casing and forming a seal between said elements to prevent passage of mercury vapor, and spring means maintaining said sealing member in sealing engagement with one of said elements, said sealing member having shiftable engagement with the other of the said elements.

7. An electrode mounting for mercury vapor rectifiers com rising the combination of an insulating bus iing element extending into the rectifier casing, an electrode element having a portion extending within the bush ing, and a metallic sealing member forming a seal between said members within the casing, the sealing contact of said sealing member with one of said elements being maintained by resilient pressure.

8. An electrode mounting for mercury vapor rectifiers comprising the combination of a bushing extending into the rectifier casing, an electrode having a portion within the rectifier casing between the'bushing and electrode, and spring means co-operating with the sealing means and electrode to maintain the former in sealing engagement with the bushing.

9. An electrode mountin for mercury vapor rectifiers com rising t e combination of an insulating bus ing extending into the rectifier casing, an electrode having a portion extending into the bushing and a sealing member forming a seal between the bushing and electrodewithin the rectifier casing, said sealing member bein shiftable longitudinally of the electrode w ile maintaining the seal.

10. An electrode mounting. for mercury vapor rectifiers com rising the combination of an insulating bus ing extending into the rectifier casing, an electrode extending through the bushing, a stop member connected to the electrode and overlapping the outer end of the bushing, a sealing member forming a seal between the electrode and bushing within the casing, and yielding pressure means cooperating with the sealing member and electrode to stress the sealing member and stop member toward the bush- 1n 51. An electrode mounting for mercury vapor rectifiers comprising the combination of an insulating bushing extending into the rectifier casing, an electrode associated with the bushing, a sealing member formin a seal between the bushing and electrode wlthin the rectifier casing, and yielding pressure means cooperating with the sealing member and electrode to press them in opposite directions longitudinally of the latter.

In testimony whereof I have signed my name to this specification.

OSKAR SEITZ. 

